Coffee maker



April 1, 1952 L. BURGESS 2,591,132

COFFEE MAKER Original Filed July 12, 1947 10 Sheets-Sheet l 292 INVENTOR L. BURGESS April 1, 1952 COFFEE MAKER 1O Sheets$heet 2 Original Filed July 12, 1947 INVENTOR MW L. BURGESS COFFEE MAKER April 1, 1952 10 Sheets-Sheet 3 Original Filed July 12, 1947 INVENTOR M A-A April 1952 BURGESS 2,591,132

COFFEE MAKER Original Filed July 12, 1947 10 Sheets-Sheet 4 zss 9 135 103 125 April I, 1952 L. BURGESS COFFEE MAKER l0 Sheets-Sheet 5 Original Filed July 12, 1947 9% WYN MN NMN NYNmN n MVN QQN mm mmN INVENTOR W L. BURGESS April 1, 1952 COFFEE MAKER l0 Sheets-Sheet 6 Original Filed July 12, 1947 INVENTOR April 1, 1952 BURGESS 2,591,132

COFFEE MAKER Original Filed July 12, 1 947 10 Sheets-Sheet 7 INVENTOR KM m April I, 1952 L. BURGESS 2,591,132

COFFEE MAKER,

Original Filed July 12,- 1947 10 Sheets-Sheet 8 .INVENTOR w M Q April 1, 1952 L. BURGESS 2,591,132

COFFEE MAKER Original Filed July 12, 1947 10 SheetsSheet 9 Fly-1 25 W April 1, 1952 BURGESS 2,591,132

COFFEE MAKER Original Filed July 12, 1947 10 Sheets-Sheet l0 33 346 jam;

INVENTOR M M Patented Apr. 1, 1952 UNITED STATES PATENT ormcs COFFEE MAKER Louis Burgess, Jersey City, N. J.

Original application July 12, 1947, Serial No. 760,599. Divided and this application October 28, 1949, Serial N 0. 124,063

6 Claims.

A. A tank from which a predetermined amount of hot water is extracted whenever the machine is operated. The water in this tank is automatically maintained at a predetermined level by a float control inlet valve and this water is automatically maintained at boiling temperature by a thermostatically controlled heating device.

B. A dispenser which delivers a predetermined amount of ground roasted coffee when the machine is operated.

C. A receptacle into which said cofiee and said water are introduced and in which they are mixed.

D. An imperforate self-dumping overflow type centrifuge into which the mixture of coffee and water flows from said receptacle and in which the mixture is separated into a clarified coffee beverage which overflows the upper lip or rim of the centrifuge and a residue of coffee grounds which is ejected from said centrifuge after said centrifuge has stopped.

E. A collector ring encircling the overflow lip or rim of the centrifuge by Which the clarified cofiee beverage is collected and from which it is conducted to a suitable receptacle.

F. An automatic timing device whereby the steps involved in the operation of the machine are carried through in sequence whenever the machine is set in operation.

The improvements to this machine constituting the present invention will befully understood from the following description read in conjunction with the drawing in which:

Fig. 1 is a side elevation of my improved coffee maker, with certain parts in section;

Fig. 2 is a plan view thereof, with certain parts removed;

3 is a cross-section through a detail of construction Fig. 4 is a vertical section along the plane IV--IV of Fig. 1;

Fig. 5 is a vertical section along plane V-V Figs. 8, '7, 8 and 9 are various detail views of parts of the construction shown in Fig. 5;

Fig. 10 is a side view of a part of the construction shown in Fig. 5;

Fig. 11 is a plan view of the showing of Fig. 10;

Fig. 12 is a broken cross-sectional view along plane XIIXII of Fig. 11;

Fig. 13 is a horizontal section along plane XIIIX1II of Fig. 1;

Fig. 14 is a partial sectional view along plane XIV-XIV of Fig. 13;

Fig. 15 is a partial sectional view along plane XVXV of Fig. 13;

Fig. 16 is a sectional view showing a detail of construction;

Fig. 17 is a view partly in diametral section of the dispenser shown in Fig. 1; I

Fig. 18 is a full bottom view of the showing of Fig. 17

Fig. 19 is a perspective view of part of the showing of Fig. 17;

Fig. 20 is a rear view of the timing device according to my invention;

Fig. 21 is a front view thereof; Fig. 22 is a right side view thereof; Fig. 23 is a left side view thereof; Fig. 24 is a plan view of the timing device of Figs. 20 to 23, showing in addition certain other details of construction;

Fig. 25 is a vertical section along plane XXV--XXV of Fig. 1;

Figs. 26, 27, 28, 29, 30, 32 and 35 are detail views showing corresponding positions of a number of cams which are part of the timing device shown in Figs. 20-24 inc.;

Fig. 31 is a top view of part of the showing of Fig. 30;

Fig. 33 is a left side view of part of the showing of Fig. 32;

Fig. 34 is a detail view with certain parts removed of part of the showing of Fig. 32.

Fig. 36 is a wiring diagram for my machine.

The parts of the machine are assembled on base 1 (Figs. 1, 2, 4 and 5) supported by suitable legs 2. Tank 3 is mounted on one end of this base and comprises vertical shell 4 carrying at its upper edge flange 5 to which cover 6 is detachably secured by screws. Water enters the tank through pipe 10 (Figs. 1 and 2) communicating with a water pressure source (not shown in the drawing). Flow into the interior of the tank is controlled by needle valve 13 (Figs. 1, 2, 4 and 13) discharging into tube I4. The operation of valve I3 is controlled by float (6 operating through arm l8 and push rod [5 in such a manner that this valve is closed when the level of water 3 in the tank reaches a predeterminedlevel indicated by I? (Figs. 1 and 4). Water level gauge glass [9 (Fig. 1) communicating at top with the open atmosphere provides convenient means to check this level. Whenever water is withdrawn from the tank, float It falls slightly, push rod I is thereby raised and water flows into the tank from tube It via pipe ill until the predetermined level IT is reached, Chamber ii is open at the bottom to receive heat from burner 22 (Figs. 1 and 4) and at its top communicates with identical stacks 23 and 2d (Figs. 1, 2, 4 and 13). The function of chamber 2! is to transfer the heat delevered by burner 22 to the water in the tank, while stacks 2S and 24. carry off the gaseous combustion products of the burner. Burner 22 receives gas through pipe 25 (Fig. l). The amount of gas is controlled by bulb or thermally responsive element 26 located in the lower part of tank 3 directly under the outlet of cold water admission tube M and operating through thermostat 2? (Fig. 1) so that whenever cold Water is admitted into tank 3 or the water in the bottom of said tank otherwise falls below the boiling temperature even though the water in- .the lower part of the tank is temporarily below the boiling point. This insures that some steam will be continuously generated in the upper part of tank 3, the use and application of which will be described hereinafter. When the water in the lower part of tank 3 is at the boiling point thermostat 21 (Fig. 1) cuts down the burner flame. The bypass of thermostat 21 is adjusted for minimum flame, such that even when the burner is cut down the necessary extent of boiling and steam evolution in the upper part of tank 3 will be maintained.

Up to this point the means described is for the purpose of maintaining a volume of water in tank 3, of maintaining at least the upper part of this water at boiling temperature, and of maintaining controlled evolution of steam therefrom. In the operation of the machine, a predetermined amount of water is abstracted from the upper part of tank 3 when the machine is operated. The equipment for this purpose in cludes container 3%) (Figs. 1, 2 and 4) located in the upper part of tank 3 below water level I? and vented into the space above said water level H by pipe 3!. Screw 29 secures pipe 35 to shell (Fig. 3), while the frustro-conical surface 35 makes liquid-tight contact with frustro conioal seat 35. The plunger is actuated by push rod 3'! operating through stuffing box 38. When the plunger is in the position shown in Fig. 3, container fail (Figs. 2 and a) is in free communication, via pipe 28, with outlet 33 and the contents of container 30 flow out of tank 3. When, however, plunger 33 is in its lowest positi0n,'outlet 39 is blocked by the poppet valve consisting of surface 35 and seat 36, now in liquid-tight contact, whereupon water flows from the interior Details of the mechanism 4 of tank 3 through port 40 (Figs. 1 and 3) and through the bore 34 of valve 32 back into container 30.

The dispenser tl which delivers a predetermined amount of ground roasted coffee is illustrated in Figs. 1, 2, l7 and 18. The dispenser comprises cylindrical bore 42 and integral therewith flange 43 and rim 44 which hold glass cylinder 35. The cylinder is surmounted by the removable'cover 46. The bottom of cylindrical bore 42 is provided with floor 4T. Upstanding shaft 48 is journaled in the exact center of this floor. Pinned to this shaft is hub 49 which carries eight radially disposed vanes 59 (Figs. 2 and 17). These vanes define eight pockets (Fig. 2) which by their rotational movement operate to progressively bring charges of cofiee over discharge port 5| in floor i'i (Fig. 18). 7 Cover plate 52 (Figs. 2 and 17) secured to cylindrical bore 62 (Fig. 17) overlays port 5| to prevent coffee from running out of said port (Fig. 18) except as transported by vanes to a position overlaying said port. To the upper part of shaft 58 there is pinned hub 55 (Figs. 2 and 17) bearing three sweeps 56 which sweep the upper surface of cover plate 52 to prevent accumulation of ground coffee thereon. I

Dispenser 4| additionally requires some means 7 for moving hub 49 and attached vanes 50. This means includes gear 59 (Figs. 17 and 18) splined to the lower end of shaft 48. This gear is periodically engaged by a hook Q I journaled at 62 to arm 63 of bracket 64. Spring (Fig. 17) serves to impel said hook into contact with said gear. Bracket 64 borne by vertical shaft 65 is bored to loosely engage stub 66 secured in and depending from floor 41 of the dispenser. As is evident from this construction, when shaft '65 and bracket 64 carried thereby are moved in one direction, hub 49 will be carried through a fraction of a complete revolution, but when shaft 65 and therewith bracket '64 move in the reverse direction, hook' 6| will merely slide over the beveled teeth of gear 59 (Fig. 18) without moving hub M (Fig. 17). In practice, I find it highly advisable that this movement be carried out gradually and progressively throughout the major part of the operating cycle of the machine. This being the case, it is evident that unless suitable provision were made, the coffee in the pocket, formed by two of vanes 50, moving over discharge port 51 (Figs. 2, 17 and 18) would fall continuously out through said discharge port. Inasmuch as the coffee must however be discharged at the commencement of the operating cycle, suitable means is incorporated to hold this charge of coffee in the dispenser until required. This means includes plate 10 (Figs. 6 and 7) pivoting about shaft 48 and slid,-

. able parallel to discharge port 5! to uncover same. Hook i2 is journaled at 13 to arm 14 of horizontal bracket 64.

' the position'of maximum advance, the pocket defined by two of vanes 50 has been brought directly over discharge port 54. At this. time slot '15 of hook 12 engages pin H on plate 70 and when horizontal bracket 64 andhook l2 actuated thereby move in the reverse direction plate E0 slides to uncover discharge port 5!! This uncovering is effected at a suitable time in the beginning of the machines cycle as will be hereinafter explained. When bracket 64 commences to return, shoulder '58 (Fig. 18) of hook T2 is engaged by dog I? resiliently pivotal about pin it against 7 the action of spring 78 one end of which isconnected to arm 8| of dog 71 and the other to stub When hook 61 reaches a 5 82 provided on the bottom of floor 41. Hook I2 .is thereby forced out of engagement with pin II and plate I returns to closed position, covering port under the influence of spring 83, one

end of which is connected to pin 84 on arm 85 of plate I0 while the other end is connected to stud '89 protruding downward from dispenser floor 41.

The further movement of bracket 64 forces dog I! out of engagement with shoulder "I6, thereby freeing hook 12. Plate I0 is supported by rigid bar 89 pivotally carried by the lower end of shaft 49.

Some of the finer grades of coffee manifest a tendency to stick together and may for this reason not be completely discharged from the space overlaying port 5I even though plate I0 has uncovered said port. This difficulty is, however, overcome by upwardly projecting teeth 90 and 9| (Fig. 17) carried by plate I0, which teeth project up into the space traversed by vanes 50 and rip and dislodge the coffee above discharge port 5| so that it is fully discharged. A perspective view of one such tooth is shown in Fig. 19. As is evident from Fig. 6, vanes 50 define slots or cutout portions 92 which enable vanes 50 to clear teeth 90, 9| in their progressive rotational movement.

The dispenser M is positioned by bracket 99 (Fig. 1) embracing cylindrical bore 42 of dispenser M, the ends of said bracket 99 being secured to shell 4 of tank 3 (Fig. l) The dispenser is thus firmly secured in position in the machine.

That part of the machine by which the predetermined volume of coffee delivered by dispenser 4| and the predetermined volume of water abstracted from tank 3 are commingled to form a mixture of hot water and ground roasted coffee appears in Figs. 1, 5 and 13. Referring to these figures, this part of the device comprises mixer I00 consisting of cone bottom receptacle IOI surrounded by casing I02 and associated means for admixing the coffee and water. Discharge outlet 5I of the dispenser is located directly above the mouth of receptacle IOI so that the charge of ground roasted coffee delivered by the dispenser falls directly into said receptacle. The predetermined volume of water abstracted from tank 3 by means hereinabove described is delivered via valve 32 into receptacle IN by spout I03 (Figs. 1, 5, 6 and 13). The hot water issues from spout I03 in a well defined stream of considerable velocity through orifice I04 (Figs. 5 and 6). This orifice may be threaded to the spout s0 that orifices of different capacity may be substituted for one another if it is desired to change the volumetric capacity of the machine. As indicated in the drawing (Figs. 5, 6 and 13) this stream from orifice I04 is discharged at a noncentral angle intermediate between vertical and horizontal and on striking the surface of the liquid already delivered into receptacle IOI it imparts a rotational movement thereto while simultaneously beating down into the liquid any ground coffee floating on the surface thereof. This angle is preferably between 30 and 60 with reference to the horizontal, for maximum efficiency. As a result the coffee and water intro- ,duced into receptacle IOI are thoroughly and efiiciently commingled by the velocity of the water introduced and without resort to a mechanical mixing device.

Suitable means is provided for discharging the mixture from receptacle IOI after it has remained in the receptacle a suitable predetermined period of time. This means comprises a valve of special and novel construction (Figs. 5 and 9). The mixer discharge outlet I05 is centrally located in the cone bottom I06 of receptacle IOI (Fig. 5). This outlet may be closed by the frustro-conical end of poppet-type plug I01. Referring to Figure 9, it can be noted that plug I01 in turn defines a small outlet or discharge orifice I08 which may be closed by conical plug I09 secured to the lower end of push rod II0 These parts are held in alignment by bore III formed in the upper end of plug I0'I in which bore push rod I I0 reciprocates. The central portion of said plug I0I is cut away leaving only two posts II4, thus permitting free access of the mixture of water and coffee to orifice I08. When the valve is in the position illustrated in Fig. 5, i. e., with push rod H0 in depressed condition, discharge outlet I05 is blocked by plug I01 and orifice I08 is blocked by plug I09. In this position the mixture of coffee and water is of course'held in receptacle IOI. At the expiration of a predetermined period of time a controlled and uniform stream of the mixture is supplied to the centrifugal separator to be hereinafter more fully described. For this purpose, the pressure on push rod H0 is released whereupon spring II5 pressing against collar II 6 pinned to rod IIO forces upwardly said rod and plug I09 carried thereby, thereby uncovering orifice I09. This position of the valve is shown in Fig. 9. The diameter of this orifice and of the rundown tube II'I (Fig. 5) are interrelated. If the rundown tube is too small the requisite rate of flow cannot of course be maintained and conversely if it be too large it will not carry a solid column of liquid, whereupon suction on orifice I00 will be lost and the rate of flow out of receptacle I 0| will fall oil rapidly with diminishing level of the material in receptacle I 0|. Within these limits the rate of flow from receptacle IOI is a function of the total heighth of liquid in said receptacle and. said rundown tube I I! and is therefore only limitedly affected by the drop in level in receptacle IIlI.

For the purpose of establishing the diameter of the orifice and of the outlet tube the following procedure is recommended. Having established the dimensions of the mixing receptacle and the length of outlet tube required to carry the mixture from the receptacle into the base of the centrifuge, an orifice is provided in the lower end of the outlet tube. Being so mounted. the ori fice will at all times be operating under a full head of liquid and the rate of flow will therefore be controlled by the size of the orifice and I by the head. Under these conditions, the size of the orifice can be varied until the desired rate of flow out of the mixing receptacle is obtained. In this way it is possible to establish approximately the correct diameter of orifice, and the size of orifice having been so established the orifice is now moved from the lower end of the outlet tube to the upper end of the outlet tube. Two procedures are now available for determining the correct size of the outlet tube to be operated in conjunction with the size of the orifice so established. In one procedure an outlet tube of transparent material such as glass may be temporarily provided and tubes of varying diameter are substituted until with increasing diameter it is found that-the tube will not carry a solid column of liquid but that the column will break and will at least partly displace the liquid in the tube, thereby reducing the hydrostatic head upon the orifice. The outlet tube to be adopted in prac- 'tacle.

tice should approach the maximum diameter at which a solid column of liquid is obtained under these conditions thereby insuring a uniform discharge of the mixture from the mixing receptacle into the centrifuge coupled with the maximum rate of discharge of the flush water hereinafter referred to. In the alternate procedure an outlet tube of metal may be used and tubes of varying diameter substituted until a diameter is reached at which the outflow from the mixing receptacle through the orifice is not uniform and sustained but pro contra falls off sharply with the reduction of liquid level in the mixing recep- Based on these observations the tube to be adopted and installed should approach the maximum diameter at which the rate of outflow from the mixing receptacle is a function of the total head within the mixing receptacle and the outlet tube and is therefore relatively unaffected by a reduction in liquid level within the mixing receptacle.

At the complete end of the operating cycle it has been found necessary to fiush out receptacle IOI and at this time and for this purpose squirts of water are tangentially introduced (Figs. 5' and '13) by nozzles H8. These nozzles are boredin small turret-s H9 spun into the inner surface of the side wall of receptacle IOI. A detail view of one such nozzle is shown in Fig. 8. Flush water is carried to said nozzles by annular ring I20 set in the top of mixer I (Fig. and the flush water is carried into ring I by tube I2I (Figs. 1 and 5). The means for the supply of flush water to tube IZI is described hereinbelow. During this stage of the operating cycle free discharge from receptacle IOI is desirable'and this is accomplished by further lifting push rod IIO so that plug I5? is unseated and the liquid passes out of receptacle IOI through the full opening of discharge outlet I05 (Fig. 5) I Inasmuch as tramp material occasionally finds its way into the dispenser. and since such tramp material might plug orifice I08 and thereby disturb the working of the machine, said orifice is surrounded by frustro-conical screen I22 (Fig. 5). This screen is of perforated metal, the perforations being approximately inch in diameter on A; inch centers. It operates to prevent tramp material finding its way to orifice I08 and also functions as a guide surface for plug I01.

The construction of the centrifugal separator and ancillary parts is shown in Figs. 5, '7, 10, II and 12. The centrifuge I23 (Fig. 5) preferably of chromium steel or stainless steel, comprises upper tubular section I24 which terminates in inwardly projecting overflow lip I25 and lower tubular section I26 of a diameter greater than section I24. The lower end I26 of centrifuge I23 is spanned by the annular closure I21 carrying the centrally located discharge tube I28. It has been found in practice that the larger particles in the coffee grind are quickly thrown out in the a base of the centrifuge and tend to accumulate at this point, but that if the centrifuge is made uniformly large enough in diameter to accommodate this accumulation, the peripheral velocity of V discharge from the overflow lip is so great as to introduce cloud'into the beverage. By. the special form of centrifuge shown in Fig. 5, the accumuminimum peripheral velocity of discharge and minimum cloud. In practice, the centrifuge isstarted in rotation so that it comes to full speed before plug I09 lifts and orifice I08 is uncovered. Thereafter the mixture of grounds and extract runs at a uniform rate through mixer outlet I05 to tube II! and is diverted horizontally from the lower end of tube II! by spinning saucer I30.

Referring to Figs. 10, 11 and 12 for details of this saucer, it can be noted that the circumference of this saucer is provided with a series of vertical teeth I31. These teeth act as an impeller ring to increase the velocity with which the mixture of ground coffee and water issuing from outlet tube II! is thrown horizontally into lower tubular portion I26 of centrifuge I23. In order to prevent coffee grounds from being retained in said saucer by the inner surfaces of said teeth, said surfaces are inclined downwards, preferably forming a continuation of the radial bevel of said saucer, and may in addition also be provided with lateral bevels as shown in the drawing (Figs. 11 and 12). Saucer I30 is carried by two posts I3l (Fig. 10) forming an upward extension of discharge tube I28, thus leaving a full opening for discharge purposes. The mixture undergoing separation accumulates in the centrifuge in tubular form. V The thickness of this tubular body is determined by the inner edge of overflow lip I25. As stated, the larger particles are thrown out in lower tubular section I25 of centrifuge I23 and with continued introduction of fresh mixture the partially separatedmixture is displaced upwardly into upper tubular section I24 of the centrifuge. The mixture introduced into the centrifuge may contain some froth and some particles which have associated air or gas bubbles. Such froth and particles might move up along the inner wall of the centrifugal column of liquid but are restrained from so doing by'a series of, for instance, four baffles I provided in upper tubular section I24 of the centrifuge (Fig. 5). Referring to Figure '7 for a detail view of one of these baflies it is noted that they are peripherally cut away to form concentric slots I35 through which the mixture passes adjacent the inner wall of upper centrifuge section I24, and are provided with central opening I31 to clear rundown tube II'I (Fig. 5), but are otherwise imperforate so that material cannot flow telescopically up the centrifuge. The baffles are secured in position in any suitable manner.

, When centrifuge I23 is placed out of rotation (by means hereinafter to be described) the coffee grounds discharged by gravity into discharge tube I28 and thence into waste pipe I33 (Fig. 5). Waste pipe I33 is supported from base I by fitting I34 (Figs. 1 and 5). The centrifuge is driven by motor I92 through belt I39 (Fig. l)

and pulley I40 (Fig. 5). 7

As mixture continues to flow into centrifuge I23 there is a continuous upward displacement of same into upper tubular portion I24 of the centrifuge and clarified beverage is thrown off from the top surface of overflow lip I25. It will be noted (Fig. 5) that the outer peripheral diameter of lip I25 is less than the bore of the upper portion'lz i of th centrifuge, thereby reducing the peripheral velocity of discharge. The clarified beverage is caught in the annular trough formed by collector ring I4I (Fig. 5). This collector ring is provided with boss I42 by which it is secured to cylindrical casing I43. By ref-'- erence tot-he partial view of collectorring I 4I contained in Fig. 15, it will be noted that the beverage discharges from said collector ring through boss I42 into accumulator I44 by means of spout I45. This spout debouches into thimble I46, forming a hydrostatic seal, the function of which will be hereinafter considered.

Accumulator I44 (Figs. 1, 2, 13, 14 and 15) comprises spaced concentric glass cylinders I41 and I48 (Fig. 1 4) closed by top and bottom end plates I49 and I50, respectively, held together by rods II. Faucet I52 (Figs. 1, 2 and 13) is provided for drawing off the coffee beverage. Bracket I53 (Fig. 14) extends downwards from end plate I49 to support thimble I46. Cover plate I54 (Fig. 13) slidable parallel to top end plate I49 provides access to the accumulator for cleaning purposes. Float I55 vertically displaceable in housing I56 (Fig. 14) is responsive to the liquid level within said accumulator. This float is provided with vertical guide pin I51, rigidly attached thereto. The operation of this float can be more easily understood by referring to the partial cross-sectional view afforded by Fig. 16. When the level of coifee beveragein accumulator I44 drops below the predetermined level, float I55 and vertical guide pin I51 rigidly attached thereto (Fig. 14) move downwards and collar I58 (Fig. 16) borne by pin I51 (Figs. 13 and 16) presses down on end I59 of channel member I60 (Fig. 16) pivoted about pin I6I secured in housing I62. End I63 of said channel member is thus raised, closing microswitch I64 (Fig. 1) by means of chain I65 (Figs. 1 and 16), thus maintaining the electrical circuit of my machine closed, as will be described hereinafter below. When coffee beverage has accumulated up to the predetermined level in accumulator I44 float I55 rises, the pressure on end I63 of lever I60 is released and microswitch I64 is allowed to open. Cam I66 (Figs. 13 and 16) is arranged in housing I62 and provided with handle I61 to turn said cam to cause it to bear down on lever end I63, thus providing manual operating means for the control of microswitch I64 (Fig. 1).

"Centrifuge I 23 is journaled in bearing I69 (Fig. 5). This bearing defines annular space I10, closed by annular ring I68, into which space oil for lubrication is introduced through oil hole I1I connecting with force-feed lubrication line I12. The oil moves to the bearing surface through hole I13. Any oil thrown off from the upper surface of bearing I69 is deflected by apron I14 into annular trough I15, from which it discharges through port I16 onto shelf I11 secured to the side wall of the centrifuge and serving to deflect the oil into annular trough I18. Similarly any oil passing away from the lower surface 'of bearing I69 is likewise deflected by said'shelf I11 into saidannular trough I18. Overflow I8I communicating with said trgugh serves to return the oil via line I82 to the oil reservoir351 (Fig.

"1) to be hereinafter described. The downward thrust of the centrifuge is taken by collar I83 (Fig. 5) secured to the side wall of the centrifuge and riding on the upper surface of bearing I69. This collar also carries depending skirt I84, the purpose of which will be hereinafter described.

After the mixture formed in receptable IOI has all flowed into centrifuge I 23, a batch of plain coffee and that there will not be a loss of yield as the result of beverage remaining in the cen trifuge. w i i When these operations are concluded, centrifuge I23 is abruptly stopped by means of brake 301 (Fig. 1) to be hereinafter described. In this case the residue of grounds and water remaining in the centrifuge continues to rotate for afew seconds until its momentum has become dissipated. This scours and cleans the inner surface of centrifuge I23 and as soon as. the momentum has been dissipated in this manner the mixture flows out of the centrifuge throughdischarge tube I28 and out of the apparatus through Waste pipe I33.

As soon as this has taken place, jets of hot water are discharged against the inner walls of receptacle MI and of centrifuge I23 thereby completing the cleaning operation.

, The means for the accomplishment of this cleaning operation comprises coil I surrounding flue H in tank 3 (Figs. 1, 4 and 13) and branching oif from water inlet pipe I0 below needle valve I3. The other end of coil I90 communicates via flush control valve I9I (Figs. 1, 2, 4, 5 and 13) with pipe I93. Pipe I93 communicates in turn with conduit I94 (Fig. 5) within casing I 02 of mixer I 00, which conduit'terminates in chamber I 91 concentrically arranged about mixer discharge outlet I05 and delivery tube II1. Flush tube I95 extends downwards from chamber I91, so as to provide an annular space concentrically surrounding rundown tube II1. This annular space is sealed off slightly above teeth I32 of saucer I30, and flush tube I 96 is provided with a multiplicity of orifices l 98 forming outlets for the flush water. Tube I21 providing flush water via nozzles H8 to receptacle IOI, as described above, branches off from pipe I93. This tube is provided with U-bend. I99 to provide a hydrostatic seal in said tube. Thus when flush control valve I9I (Figs. 1, 4 and 13) is actuated by means hereinafter to be described, water which has been heated in coil I90 to 100 C. and which is under the full pressure of the main water supply, for instance the municipal water system, discharges through orifices I98 and nozzles II8 (Fig. 5) thereby flushing out receptacle IOI and centrifuge I23 respectively.

As hereinbefore stated, burner 22 (Figs. 1 and 4) heating the water in tank 3 is so controlled, thermostatically, that some boiling is always taking place in the upper part of tank 3 with consequent generation and evolution of steam. This steam passes downwardly through vertical pipe 20I (Figs. 1, 2 and 13) and thence via horizontal pipe 202 into casing I02 (Figs. 2, 5 and 13). Some of the steam condenses to maintain receptacle I0l, centrifuge I23, collector ring I and associated parts (Fig. 5) at 100 C. thereby insuring eflicient operation regardless: of the standby periods and also sterilizing centrifuge I23 and collector ring I4I. One part of theexcess steam moves downwardly through the bore of centrifuge I23 and out of the apparatus through discharge tube I28 and waste pipe I33 (Fig. 5). Any air that may have been originally in the centrifuge or carried into it from the mixture theretofore separated is thus displaced by steam, thereby eliminating cloud in the finished beverage which would otherwise result .from air in the system. The steam is prevented from flowing into the centrifuge bearings by depending skirt I84 (Fig. 5), which operates as a hydrostatic seal, the water for this seal being supplied by the condensation effected at casings I02 and I43. Whenever centrifuge I23 is started this water is thrown out by centrifugal force and flows through drain 204 and conduit 205 to waste pipe I33. Another part of the excess steam passes via conduit 206 (Figs. 5 and into the annular space defined by glass cylinders I41 and I48 of accumulator I44 (Fig. 15), thus providing a steam jacket for the coffee beverage contained within said accumulator. Condensate flows to waste pipe I33 through drain 208 (Fig. 14) and pipe 205 (Fig.5). The hydrostatic seal provided by thimble I46 (Figs. 14 and 15) prevents steam passing into the central portion of accumulator I44 through spout I45.

Having described the constituent parts of the machine by which the beverage is produced I now describe the control or timer by which these constituent parts are operated in the correct temporal sequence. The timer 220 (Figs. 1 and -24) comprises pulley 22I driving, through three reduction gears (not shown in the drawing) contained in reduction gear housing 222, worm 223 which in turn drives gear 224 splined onto jackshaft 226. Pulley 22I is driven by V-belt 225 from motor 221 (Fig. 1). Referring to Figs. 20-

'24,. jackshaft 226 carries seven cams by which the said temporal sequence is determined which cams will be hereinafter more particularly described. Said jackshaft 226 is journaled in holes bored in the uprights 226' and 229, which in turn are suspended from the underside of base I (Fig. 1). These uprights are mounted on reservoir cover plate 362', and are further laterally supported by cross-plates 2I6 and 2I1'. Motor 221 is carried laterally by cross-member 230 secured to legs 2 (Fig. 1). Cam rider shaft 23I is likewise journaled in holes bored in uprights 220 and 229. .Shaft232 is secured in brackets 231 supported on vertical panel 233, this shaft serving as pivot for mercury switches 234 and 235 the purpose of which is hereinafter explained. Panel 233 is cut out to permit the pivoting' of these switches. Trough 236 is supported by staybolts 2I8 and 2I9 secured between uprights 2'28 and 229. Thistrough (Figs. 1 and 20-24) functions to retain a bath of oil or grease into which the cams dip and which, therefore, provides them with adequate lubrication.

Jackshaft 226 is so geared to timer motor 221 that it and the cams carried thereby make a complete revolution. in one cycle of the apparatus. The construction of the cams will be described by reference to one specific embodiment of the apparatus which has a cycle time of 90 seconds. Inthis' specific embodiment, centrifuge I23 (Fig. 5) has an overall inside length of thirteen inches. The: inside diameter of the base portion I26 is three inches, inside height of this portion two andthre'e sixteenths inches, inside diameter of. upper portion I24 of the centrifuge one and one-half inches, inside diameter of the overflow lip- I25 one inch. Rundown tube 1 is of inch bore and orifice I08 of plug I01 is offs inch bore. This centrifuge is operated successfully at about 5000 R. P. M- with an output of five cups of finished beverage per cycle. The

centrifuge may, of course, be operated at higher or lower speeds, if desired, and the output. per cycle may be increased or decreased, depending upon the strength desired. With the cycle time and cycle output described, the amount of coffee introduced maybe in the proportion of one pound of coffee to about cups of finished beverage v timer motor 221.

I2 or about one pound of coiiee to about 45 cups of finished beverage, or in any intermediate proportion.

We are now prepared to discuss the specific designs of the cams and cam riders whereby the requisite control is obtained. Referringto Figs. 20, 2.1, 24 and especially 35, the function of cam 240 is to maintain the precise cycle time of the apparatus and to insure that whenever started in operation, it will continue to operate until its full cycle is completed. Rider 24I is pivotally carried by shaft 23I while projection 243 rides on the surface 244 of cam 240. Rider 24I is connected through link 245 to rocker 246 pivotally carried by shaft 232. Rocker 246 carries mercury switch 234. By reference to Fig. 36 which is a diagram of the wiring circuit, it is seen that mercury switch 234 is in series with Thus, whenever timer motor 221 is started in operation, as by the microswitch I64 controlled manually or by accumulator float I55, and hence projection'243 climbs from surface 242 onto surface 244,. mercury switch 234- will be carried to the o-n-circuit position and motor 221 will continue in operation until the entire cycle has been completed and the cam rider MI is returned again down onto surface 242 by the tension of spring 241. One end of said spring is connected to rocker 2-46 and the other end to panel 233. At this point if switch I64 (Figs. 1 and 36) is open, timer motor 221 and the apparatus come to a complete stop.

The next step in the operation of the apparatus is effected by cam 249 (Figs. 20-24). A detail view of this cam is shown in Fig. 26. This cam carried by jackshaft 226 controls the operation of the mixer outlet valve I05 shown in Figs. 5 and 9. When timer motor 221 is s-tartedprojection 250- of rider 25I: carried by shaft 23I climbs to the surface 252 of cam 249, thereby lifting push rod 253. This push rodv is connected via link 254 (Fig. 1) pivoted on bracket-255- secured tobase I, with rod 248. Arm 256 extends horizontally from rod 248, its outer end being displaceable between: collars 251 and 258 on push rod H0 (Fig. 1). Thus when push rod 253 is lifted, arm 256 is depressed and strikes collar 258, thereby pressing downwardly upon: push rod 0' and seating plug. I09 in orifice I-0-8 (Fig. 5). Projection 250 will be about half-way up the inclined surface of cam 24!! when projection 243 (Fig. 35) attains its full lift. This insures that the load on timer motor 221 will be staggered andv that-mixer outlet valve I05 will notbe fully closed: until the machine cycle; has been definitely started. At the expiration of 42 seconds from the time of initial. contact projection 250 runs off surface 252 (Fig. 26') onto surface 259 by reasonof the pull exerted by spring 260 connected between rider 25I and oil reservoir'cover plate 362-. In. this way pressure on collar 258 (Figs. 1 and 5) is relieved and orifice I08 is permitted to beopened by the upward pressure of spring: H5 operating against collar I:I6 (Fig. 5')- At 83 seconds after the time of initial contact,- projection 250' runs off surface 259 (Fig. 26') onto'surface 26I'. The further' drop push rod 253 causes arm 256 (Fig. 1) to' contact with and lift collar 251, thereby lifting the entire valve assembly- I01 off of seat I05 and making available the full discharge opening from the bottom of receptacle I-0I.

Returning to Figs; 20-24,. the next cam in point of interest is. 26-5. A detail view of this cam is shown in: Fig. 29. This cam controls the operation of the mixer water inlet valve 32 shownin Fig. 1. When projection 250 (Fig. 26) has just attained its maximum lift, projection 286 (Fig. 29) of rider 25'! carried by shaft 23!, is about half-way up the surface 268 of cam 285. Projection 266 continues to ride on surface 208 until 20 seconds after the time of initial contact, whereupon projection 266 is returned to surface 269 by the pull exerted by spring 264. While projection 266 was in the elevated position, push rod 21! was lifted, thereby lifting connected yoke 212 (Fig. 1) and opening valve 32 (Fig. 13). In a machine of the specific capacity described, orifice I04 (Fig. 5) is so chosen that approximately five cups of water pass into receptacle I! during the period that valve 32 is so opened. At the expiration of 20 seconds, valve 32 is closed by the return of push rod 21! and remains closed until seconds after initial contact when projection 286 runs up onto surface 213 (Fig. 29) of cam 285. It continues to ride on this surface 213 until 6'7 seconds after the time of initial contact, whereupon projection 268 runs down onto surface 214 and valve 32 is again closed. From 2.5 to 3 cups of water will have entered receptacle Ill-I during this period.

Having described the means for closing the mixer outlet valve and for introducing the water, it is now in order to describe the means for introducing the ground coffee.

I have already described the dispenser (Figs. 1, 17 and 18) and how by a movement OIf rod 65 and bracket 64 in one direction the hub 49 was turned during one operating cycle and how by the reverse movement of rod 65 and bracket 64 at the commencement of a succeeding cycle the bottom closure plate I0 was moved horizontally to uncover dispenser discharge outlet 5! thereby dropping a batch of coffee into receptacle IOI.

These operations are controlled by cam 280 (Figs. 20-24). 30. Roller 28! of rider 282 pivotally mounted on shaft 23! runs on surface 283 of cam 280. Rider 282 is provided with bell arm 286 the outer end of which is developed as yoke 28! (Fig. 31) to hold pin 288 on which double clevis 289 is pivoted. Shaft 65 extending through an orifice in base I (Figs. 1 and 30) and secured thereby against translational movement is pivotally connected to said clevis 289 by yoke arm 2'90 (Figs. 30 and 31). During the operation of the machine, roller 28! is progressively lifted by surface 283 thereby forcing link 289 in the direction indicated by arrow 284. The effect is to move arm 290 and rod 65 through an angle of about 60. It is this movement which (Figs. 17 and 18) turns the hub 49 of the dispenser. The actual rotational movement of the wheel is only the overrun of 15 is desirable, however, to make certain that hooks 6! and I2 (Fig. 18) make proper engagement respectively with gear 59 and pin II. At the expiration of a machine cycle, cam 280 and rider 282 are in the positions indicated in Fig. 30. When a machine cycle is started, roller 28! runs down surface 29! of cam 280. This obviously permits clevis 289 to move under the action of spring 285 (Fig. 1) (one end of which is connected to shaft 85 and the other to base I) in the reverse direction to that indicated by arrow 284. The corresponding movement of rod 65 (Figs. 1, 17 and 18) operating through bracket 64 moves hook 6! to the position shown in Fig. 18, thereby opening bottom closure plate 10 and dropping a charge of coffee from the dispenser. This operation takes place after mixer outlet I05 (Fig. 5) has been fully closed and before the water from orifice I04 has A detail view of this cam appears in Fig.

'(Figs. 21, 23 and 32 by pin 332.

charge of this water may operate to drive the coffee below the surface of the water accumulated in receptacle I0! and to insure complete mixing. As hereinbefore pointed out the movement of rod caused by the progressive lift of roller 28! also operates to throw hook I2 out of engagement with pin 1! (Fig. 18) thereby permitting the pull exerted by spring 83 to close door I0.

Cam 300 (Figs. 20-24), next to be considered, controls the operation of centrifuge motor 292. This motor operating through pulley 293 drives pulley I40 (Figs. 1 and 5) of centrifuge I23 via V-belt I39. For this purpose motor 292 is secured to leg 2 of base I (Fig. 1). Referring to Fig. 28, jackshaft 226 carries cam 300. Cam rider 30! pivotally mounted on rod 23! has projection 382 which rides on the surface of this cam. Rider 30! is connected through link 30!! to rocker 305 pivotally carried by shaft 232.. Rocker 305 carries mercury switch 235. As projection 302 rides up onto the elevated portion 303 of this surface, link 304 changes the angle of rocker 305, thereby throwing mercury switch 235 carried thereby to the on-position. As is evident from the wiring diagram of Fig. 36, this switch is in series with and controls centrifuge motor .292. To bell arm 308 (Fig. 28.) of rider 30! there is pivoted link 3I4, the other end of which is pivoted about pin 3I6 provided in yoke 3l5 of brake drum 301 (Figs. 24 and 28). Before switch 235 reaches the on-position, link 3I4 is retracted, thereby pulling brake drum 301 and brake surface 308 away from engagement with the outside of lower section I28 of centrifuge I23 (Fig. 1). As shown in Figs. 22-24 brake drum 301! is slidably carried by rods 309 and 3I0 mounted in uprights 228 and 229. Springs 3!! and 3I2 urge brake drum 30'! toward lower section I26 of centrifuge I23 and as soon as projection 302 rides off of the elevated surface 303 these springs apply the brake and arrest the rotation of the centrifuge; simultaneously spring 3I3 connected between rocker 305 and panel 233 returns mercury switch 235 to the off-position, thereby killing centri fuge motor 292.

After centrifuge motor 292 and centrifuge I23 have stopped, sufficient time is allowed for the material remaining in the centrifuge to lose its rotational movement and run out of the device through discharge tube I28 and waste pipe I33 (Fig. 5). Shortly thereafter receptacle I8! and .centrifuge I23 are flushed out through spray nozzles H8 and orifices I98 (Fig. 5) and for this purpose flush control valve I9! is actuated by pushing upwardly valve stem I 92 (Fig. 1). To this end push rod 320 (Fig. 1) is forced upwardly so that collar 32! bourne by the end thereof is raised from its seat on top of sleeve 322 and actuates valve stem I92. The mechanism by which this is accomplished is shown in Figs. 32 and 33 in a detail showing of part of the construction of Figs. 1 and 20-24. Cam 330 mounted on shaft 226 defines a discontinued surface of progressively increasing radius. As the cam revolves, during the machine cycle, it progressively forces upward lever 33! pivotally connected to spacer 328 on the side of upright 229 This upward movement compresses coil spring 333 positioned by retainers 348 and 341 against lever 334 which is also pivotally connected to said spacer 328- by pin 335. Attention is called to the :fact that the pivot points of levers 33! and 334 do not lie in the same vertical plane (Fig. 32). Lever 334 15" cannot move upwardly because it is restrained by trigger 336 pivotally connected to spacer 329 on the side of upright 229 (Figs. 20 and 21) by pin- 331. At the exact moment at which it is desired to actuate the fiush valve, trigger 336 is forced off of the end of lever 334 by pin 338, thereby releasing lever 334 and actuating push rod 320. The angular divergence between levers 334 and 33! is, however, limited by roller 339 rotatably supported by pm 340 in oversize bore 34!.' Leaf spring 342 tends to hold roller 339 in the position shown in Fig. 34. Housing 343 carried by lever 33! supports pin 340 and spring 342. As soon as the end of lever 33! runs off of the elevated surface 344 of cam 330 both levers 33! and 334 drop and flush control valve I9! is thereby closed, and upon further rotation of cam 330 trigger 336 is reset by means of spring 345 attached between said trigger and stub 346. As the result of this construction the flush valve is either fully on or fully off, i. e., there is no intermediate period in which water is being discharged without a vigorous flushing effect and the total time the valve is open may be closely determined by adjustment.

Next to be considered is the force-feed lubrication system for the centrifuge bearings. Referring to Fig. 27, cam rider 350 pivotally carried by shaft 23! has projection 35! which rides on the surface of cam 352, mounted on shaft 226. The rotational movement of cam 352 operating through link 353 alternately raises oil pump piston 354. The reverse movement of piston 354 is effected by spring 356. As can be noted from Fig. 27, there are four strokes of piston 354 during each machine cycle. These movements discharge oil from reservoir 351 through side outlet 36!) and tube I12 (Fig. 1) into annular space I10 (Fig. in the upper surface of cent'rifuge bearing I69. Oil returns to reservoir 351 from annular trough I19 (Fig. 5) through return line I82 (Fig. 1). Oil reservoir cover plate 392 is supported from base I by uprights 228 and 229 (Figs. 20-24), and reservoir 351 is suitably secured to the bottom of said cover plate.

Referring to Fig. 25 for a longitudinal vertical section through oil reservoir 351 and cover plate 362, the reservoir may be periodically replenished through fill pipe 363. The reservoir is provided with a riser 365 which is connected by duct 366 with the main body of reservoir 351. If water finds its way into the oil reservoir, as, for example, the result of leakage, carelessness in cleaning, or possibly leakage of steam into the main bearings, the water accumulates in the lower part of reservoir 351 and the oil is thereby lifted into risers 368 and 310'until the compound head of the water and of the oil resting thereon counterbalances the hydrostatic head of a column of water in riser 3'65 extending up to outlet 364. Any further accumulation of water is then automatically rejected through outlet 364 without at any time interfering with normal hearing lubrication. Piston 354 reciprocates in liner 369 provided in pump block 31!, said liner extending upwards through riser 368 (Fig. 25).

The cams illustrated are of suitable outline for a coffee maker operating on an overall 90 second cycle with a production of 5 cups of finished beverage per cycle. The following are the approximate times maintained by a timer carrying such cams and which times have been found entirely satisfactory.

Seconds After Commence meiit of Cycle Mercury switch 234 and timer motor Determined by project-ion 243 riding up onto surface 244 of cam 240 (Fig. 35).

(a) Mixer discharge outlet I05 closes:

Determined by projection 250 riding up onto surface 252 of cam 249 (Fig. 26).

(b) Mixer inlet valve 32 opens:

Determined by projection 296 riding up onto elevated surface 268 of cam 265 (Fig. 29).

Dispenser outlet plate 10 opens:

Determined by roller 28! running down surface 29! of cam 289 (Fig. 30).

Dispenser outlet plate 10 closes:

Determined by roller 28! running onto surface 283 of cam 280 (Fig. 30).

Mixer inlet valve 32 closes:

Determined by projection 266 riding down oifelevated surface 268 onto surface 269 of cam 265 (Fig. 29).

Mercury switch 235 and centrifuge motor 292 on:

Determined by projection 302 running up on elevated surface 303 of cam 300 (Fig. 28).

Mixer outlet orifice I08 (Fig. 9)

opens:

Determined by projection 25!! running off of elevated surface 252 onto surface 259 of cam 249 (Fig. 26).

Mixer inlet valve 32 opens:

Determined by projection 265 riding up onto elevated surface 213 of cam 265 (Fig. 29).

Mixer inlet valve 32 closes:

Determined by projection 255 riding down Onto surface 214 of cam 265 (Fig. 29).

Mercury switch 235 and centrifuge motor .292 off and brake 301 applied:

Determined by projection 302 running off of elevated surface 303 of cam 300 (Fig. 28).

Mixer discharge outlet I05 opens:

Determined by projection 250 running off of surface 259 onto surface 26! of cam .249 (Fig. 26). v

Flush valve I9! opens:

Determined by pin 33!! of cam 330 releasing lever 334 from engagement with trigger 336 (Fig. '32) (a) Flush valve I9! closes:

Determined by lever 33! running down off of elevated surface 344 of cam 330 (Fig. 32).

(1)) Mercury switch 234 and timer motor 221 off: I

Determined by projection 243 running off of surface 244 down onto surface 242 of cam 240 (Fig. 35).

The times for the actuation of oil pump 355 are not critical. It is, however, desirable to introduce the first slug of oil before centrifuge motor 292 is started.

The operation of my improved coffee maker will be evident from the foregoing description. As soon as the machine is up to temperature which will be evident from the appearance of steam at the waste pipe I33 (Fig. 5) thereby showing that the water in tank 3 is up to the boiling point and that the centrifuge is at a temperature of 100 C., the machine is ready to operate. The dispenser should be charged with ground coffee and for this purpose a relatively fine grind of the order of a corn-meal grind will be found satisfactory. The machine will continue to operate so long as the circuit controlling timer motor 22! is energized by float or manually controlled microswitch 164 (Fig. 36). The residue of coffee grounds rejected from waste pipe 133 may be discharged in any suitable manner. The preferred practice in this regard is to drop the effluent directly into a waste pipe communicating with the sewer.

The foregoing description is furnished by way of illustration and not of limitation, and it is, therefore, my intention that the invention be limited only by the appended claims or their,

equivalents wherein I have attempted to claim broadly all inherent novelty.

I claim:

1. In a coffee maker including a centrifuge f the imperforate overflow self-dumping type having an inwardly project'ng overflow lip at the upper end thereof and a centrally positioned discharge outlet at the lower end thereof defining an opening of lesser inside diameter than said overflow lip, a receptacle, a rundown tube extending from said receptacle into said centrifuge, a dispenser surmounting said receptacle, a timer, means controlled by said timer for introducing a predetermined amount of water and means controlled by said timer for transferring a predetermined charge of ground roasted coffee from said dispenser into said receptacle, means for comingling said predetermined amount of water with said coffee in said receptacle to form a mixture, and means controlled by said timer for starting said centrifuge in rotation and for arresting the rotation of said centrifuge at a predetermined time, the nnprovement of means controlled by said timer for introducing a second predetermined amount of hot water into said receptacle following substantially the expiration of the time required for said mixture to run down into said centrifuge during the time in which said centrifuge is in rotation.

2. The improvement according to claim 1 in which said second amount of water is at least substantially equal to the centrifugal volumetric capacity of said centrifuge.

3. The improvement according to claim 1 in which said second amount of water is at least substantially equal to the centrifugal volumetric capacity of said centrifuge and the time of introduction of said second amount of water is so coordinated with the rate of flow out of said receptacle through said rundown tube that a volume thereof at least substantially equal to the centrifugal volumetric capacity of said centrifuge passes downwardly through said rundown tube into the lower end of said centrifuge during the time in which said centrifuge is continued in ro tation.

c. In a coffee maker including a centrifuge of the imperforate overflow self-dumping type having an inwardly projecting overflow lip at the upper end thereof and a centrally positioned discharge outlet at the lower end thereof defining an opening of les or inside diameter than said overflow lip, a receptacle, a rundown tube extending from said receptacle into said centrifuge, a dispenser surmounting said receptacle, a timer, means controlled by said timer for introducing a predetermined amount of water and means controlled by said timer for transferring a predetermined charge of ground roasted coffee from said dispenser into said receptacle, means for comingling said predetermined amount of water with said coffee in said receptacle to form a mixture, and a valve operated by said timer controlling flow out of said receptacle through said rundown tube, and means controlled by said timer for starting said centrifuge in rotation and for arresting the rotation of said centrifuge at a predetcr-- mined time, the improvement of means controlled by said timer for introducing a second predetermined amount of hot water into said receptacle following substantially the expiration of the time required for said mixture to run down into said centrifuge and during the time in which said centrifuge is in rotation.

5. The improvement according to claim 4: in which said second amount of water is at least substantially equal to the centrifugal volumetric capacity of said centrifuge.

6. The improvement according to claim 4 in which said second amount of water is at least substantially equal to the centrifugal volumetric capacity of said centrifuge and the time of introduction of said second amount of water is so coordinated with the rate of flow out of said receptacle controlled by said valve that a volume thereof at least substantially equal to the centrifugal volumetric capacity of said centrifuge passes downwardly through said rundown tube into the lower end of said centrifuge during the time in which said centrifuge is continued in rotation.

LOUIS BURGESS.

REFERENGES CITED The following references are of record in the file 

